Evaluation of Embedded Real-Time Operating Systems for Mission-Critical Applications in Nigerian Power Distribution Networks

Automated fault management and protection relaying in Nigerian power distribution networks require embedded control systems with real-time deterministic performance guarantees, and the selection of an appropriate real-time operating system for these applications lacks a Nigeria-specific evaluation framework. This study evaluated three embedded real-time operating systems (FreeRTOS, VxWorks, and Zephyr RTOS) for suitability in mission-critical power distribution automation applications, with reference to requirements defined by Eko Electricity Distribution Company and Ibadan Distribution Company. A professional evaluation methodology based on IEC 61850 automation standard requirements was applied, assessing each RTOS against seven criteria: task scheduling determinism, interrupt latency, memory footprint, communication stack support (Modbus RTU, IEC 60870-5-101, DNP3), hardware platform compatibility (ARM Cortex-M4 and ARM Cortex-A7), vendor support and documentation quality, and licensing cost for commercial deployment. Benchmark tests were implemented on STM32F429 (Cortex-M4) and STM32MP157 (Cortex-A7) platforms. FreeRTOS achieved the lowest interrupt latency at 0.9 microseconds but lacked native IEC 60870-5-101 support. VxWorks provided the most complete protocol support and vendor assurance but at prohibitive licensing costs for distribution company budgets. Zephyr RTOS showed competitive interrupt latency at 1.2 microseconds, strong growing protocol library support, and permissive Apache 2.0 licensing. The study recommends Zephyr RTOS as the most suitable platform for Nigerian power distribution automation development and proposes a phased implementation roadmap for DisCo automation projects.

Keywords: real-time operating system, power distribution automation, embedded systems, Nigeria electricity, RTOS evaluation